Our work coosists of elucidating the mechanism(s) of cellular transformation induced by acute leukemia viruses. Our progress of future plans are: a) To isolate temperature sensitive mutants of Avian myeloblastosis virus (AMV), Avian erythroblastosis virus (AEV) and Avian myelocytomatosis virus (MC29). b) To identify the target cell(s) for the avian carcinoma viruses. c) To pursue our studies on the differentiation of the leukemic cell.